Apparatus for compressing laminated cores

ABSTRACT

An assembly for compressing laminated articles, such as stator cores for dynamoelectric machines. There is provided an assembly including a doughnut-shaped electromagnet and a tapered nonmagnetic plug mounted within the electromagnet. A core, previously coated with a material intermixed with magnetic particles, is slipped over the plug and moved by suitable mechanical means toward the center of the electromagnet while the electromagnet is energized. The resultant magnetic field attracts the core to the center of the electromagnet. Also mounted in the assembly are spring-biased clamps which cooperate with adjustable stop members for clamping the core therebetween, thereby mechanically compressing the laminations of the core together. The magnetic field produced by the electromagnet magnetically compresses the laminations and also draws the coating material intermixed with magnetic particles to selected surfaces of the core, thereby forming an increased thickness of material on those surfaces.

United States Patent [72] Inventor Har0ldL.Fritzsche Fort Wayne, Ind. 21Appl.No. 802,861 [22] Filed Feb.27, 1969 [45] Patented May25, 1971 [73]Assignee General Electric Company [54] APPARATUS FOR COMPRESSINGLAMINATED CORES 6 Claims, 7 Drawing Figs. [52] U.S.Cl 29/205, 29/203,29/596, 29/609, 310/45 [51] Int.Cl ....l-l02k15/00 [50] FieldofSearch29/596, 598, 609, 205, 203; 310/45; 156/222 [56] References Cited UNITEDSTATES PATENTS 1,025,318 5/1912 Sharp 269/8 1,090,920 3/1914 Knight29/205 2,443,582 6/1948 Lendoetal.... 113/99 2,477,297 7/1949 Gilesetal90/59 3,122,667 2/1964 Bacin 310/45 3,215,966 11/1965 Lordetal.29/609(X) 3,513,527 5/1970 l-loy ABSTRACT: An assembly for compressinglaminated articles, such as stator cores for dynamoelectric machines.There is provided an assembly including a doughnut-shaped electromagnetand a tapered nonmagnetic plug mounted within the electromagnet. A core,previously coated with a material intermixed with magnetic particles, isslipped over the plug and moved by suitable mechanical means toward thecenter of the electromagnet while the electromagnet is energized. Theresultant magnetic field attracts the core to the center of theelectromagnet. Also mounted in the assembly are springbiased clampswhich cooperate with adjustable stop members for clamping the coretherebetween, thereby mechanically compressing the laminations of thecore together. The magnetic field produced by the electromagnetmagnetically compresses the laminations and also draws the coatingmaterial intermixed with magnetic particles to selected surfaces of thecore, thereby forming an increased thickness of material on thosesurfaces.

PATENIED m sum 1 or 2 INVENTOR. ffiroldLFr/zIsc/n.

BY %.M-

148 tar/19y PATENTED m2 5 I971 SHEET '2 [IF 2 INVENTOR.

Hamid L.Fritz3 BY Attorney.

l APPARATUS FOR COMPRESSING LAMINATED CORES CROSS REFERENCE TO RELATEDAPPLICATIONS The following copending applications assigned to the sameassignee as the present application are expressly incorporated byreference in the present application:

Method and Apparatus for Compressing Laminated Article While Applying aProtective Coating Thereto, Marion W. Sims, Ser. No. 803,036, filed Feb.27, 1969 Method and Apparatus for Producing a Protective Coating on theSurface of a Manufactured Article, Harold L. Fritzsche, Ser. No.803,036, filed Feb. 27, 1969 BACKGROUND OF THE INVENTION This inventionrelates to apparatus for compressing a laminated magnetic article, suchas a stator core, which has been coated with a material intermixed withmagnetic particles, which material forms an adherent integral protectivecoating on the article.

In the fonnation of bondable protective coatings on selected surfaces ofa laminated article, for example, fonnation of an insulating resin layeron slot walls, selected corners, and edges of a magnetic stator core,one of the more attractive approaches, especially from the standpoint ofarticle surface coverage and overall cost, is that disclosed in U.S.Pat. No. 3,136,650, issued to Frank C. Avila on June 9, 1964. In oneform of this approach, magnetic particles in a liquid layer of fusiblecoating material are magnetized to cause the layer to build up or becomeof increased thickness than would otherwise occur at selected surfacesof the article (e. g., comers and edges).

SUMMARY OF THE INVENTION An object of the invention is to provide animproved arrangement for compressing a laminated article.

Another object of the invention is to provide such an arrangement inwhich the laminated article may be rapidly and efficiently transferredto an assembly which automatically mechanically and magneticallycompresses the laminated article while a protective coating on selectedsurfaces of the article is being drawn to selected surfaces of thearticle to provide an increased thickness of material on those surfaces.

The subject matter of the invention and the above and other objects areparticularly pointed out and distinctly claimed in the concludingportion of the specification. The invention itself, however, both as toits organization and method of operation, together with further objectsand advantages thereof may best be understood by reference to thefollowing description taken in conjunction with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view ofone form of the improved apparatus for compressing laminated articlesshown in combination with a suitable means for inserting the articleinto the apparatus;

FIG. 2 is a view along lines 2-2 in the direction of the arrows in FIG.1;

FIG. 3 is a sectional view taken along line 3-3 in FIG. 1;

FIG. 4 is a sectional view taken along line 4-4 in FIG. 1;

FIG. 5 is an enlarged fragmentary view of a part of the laminatedarticle in the illustrated exemplification after a coating has beenformed on selected surfaces thereof;

FIG. 6 is a sectional view taken along line 6-6 in FIG. 5; and

FIG. 7 is a view in section taken along line 7-7 in FIG. 5.

DESCRIPTION OF A PREFERRED EMBODIMENT FIG. 1 illustrates a preferredembodiment of the invention in the form of an assembly 10 having ahousing 12 fixed to a suitable support member 14 which, for example, maybe the dialplate or turntable of a rotary-indexing assembly portion of aconveyor as illustrated in the aforementioned Fritzsche copendingapplication. The housing 12 may be fixed to 2 member 14 by suitablefastening means, such as bolts 16. Circumferentially spaced abouthousing 12 are a plurality of cooling fins l8.

Mounted within housing 12 is a doughnut-shaped electromagnet assembly 20consisting of a hollow annular magnetic pole piece 22 enclosing asubstantially toroid-shaped coil 24 having external leads 26 connectedto opposite ends of the winding forming the coil. Fixed to the innerperiphery of pole piece 22 is a collar 28 having a bore therein forreceiving a nonmagnetic slightly tapered plug 30. Plug 30 is fixed tocollar 28, for example, by welding. Plug 30 is tapered such that it hasa smaller diameter at its left end as viewed in FIG. 1.

Collar 28 contains four equally spaced bores or holes 32 for receivingcorresponding stop members 34 which are fixed to a flange 36 on a ring38. Ring 38 is adjustably mounted on plug 30 in order to accommodatelaminated articles, such as a core 40, of different thicknesses. Asetscrew 42 permits the axial adjustment of the fingers 34 along theplug 30.

Formed in the support member 14 are four bore holes 44 which receivefour corresponding rods 46 which are fixed to a spider assembly .48which in turn is fixed to a reciprocable drive shaft 49 which, forexample, may be connected to the piston of an air cylinder assembly.Mounted in each bore hole 44 is a spring 50 which bears against a flange52 fixed to each rod 46. These springs function to bias spider assembly48 to the right as viewed in FIG. 1 and as indicated by the dotted linein position of the assembly. Each rod 46 passes through a bore formed inhousing 12 and aligned with the corresponding bore 44 in member 14.Fixed to the opposite end of each rod 46 is a C-shaped clamp member 52.Also fixed to each shaft rod is a pin 54 which rides in a camming slotformed in the housing 12.

In operation, before a core 40 or other laminated article is,

placed on the tapered element, e.g., plug 30, the spider assembly 48 ismoved to the left against the bias of spring 50,. thereby moving theC-shaped clamp members 52 to the left as.

indicated by the full line positions in FIG. I. The pins 54 on the rods46 slide in a suitably shaped camming slot to rotate the rods in such amanner that the fingers 52 are also rotated outwardly away from the plug30 to the full line position shown in FIGS. 1 and 4, thereby permittinga core 40 to be placed on plug 30 without striking the clamps 52.

Prior to loading onto on a suitable support and masking assembly 56 asdescribed in the aforementioned Fritzsche application. A suitabletransferring assembly 58, as also described'in detail in the aforementioned Fritzsche application, may be used to transfer the core from theassembly 56 to the plug 30. At the time the core is being transferred tothe plug 30, electromagnet assembly 20 is energized by supplying directcurrent to the leads 26 to energize the coil 24 and create a magneticfield which assists in the transfer of the core 40 to the plug 30 andmore specifically as-, sures that the core 40 is centrally positionedwithin the electromagnet assembly as shown by the dotted line positionof the core in FIG. 1. Since the magnetic field of such a doughnutshapedelectromagnet is strongest at its center, the core will be; naturallyattracted to the center position. I

In order to set up assembly 20 to receive a core of a particular stacklength in the proper position within the assembly; setscrew 42, afterthe core 40 is suitably positioned within the electromagnet assembly 20,is loosened. The ring 38 is then adjusted axially of the plug 30 untilthe stop members 34 bear against one side of the for a given size core,it need not be repeated for subsequent cores of that size when usingassembly 20 in continuous manuretract to the right under the forceprovided by the bias of springs 50. Clamps 52 move into assembly 10 androtate inwardly to bear against the opposite side of the core 40 asillustrated in FIGS. 1 and 4 by the dotted line positions of the clamps52. Consequently, the laminations of the core are mechanicallycompressed together primarily in the yoke sec.-

plug 30, the core 40 may be supported core 40. Once this has beenestablished tion of the core by the cooperation of the clamps 52 and theAfter the core has been properly positioned within the electromagnetassembly and compressed as just described, and with the coating being inliquid form of the type discussed in the Avila patent, the magneticfield produced by electromagnet assembly then-draws the coating materialhaving magnetic particles therein on the heated core 40 to selectedsurfaces of the core 'to form increased thickness of material at thosesurfaces inthe manner described in more detail in the aforementionedAvila patent and copending Sims application. 1

FIGS. 1 and 2 also illustrate the details of the transferring assembly58 which is described in the aforementioned Fritzsche copendingapplication. Briefly, a support frame 60 is pivotally mounted to a block62 by means of a pin 64. A pair of fingers 66 are pivotally' mounted onthe frame 60 and are adapted to ride upon the surface ofv the coresupport and masking assembly 56 and to engage one side of the core 40.This double pivot mounting permits the fingers 56 to apply an even forceto the core even if the core surface should be uneven. To transfer thecore 40 from assembly 56 to the plug 30, a force is applied to anextension 66 of the frame 60 to force the transferring assembly 58 tothe right as viewed in FIG. 1, thereby causing the fingers 66 to engagethe side ofthe core and transfer it to the tapered plug 30.

FIGS. 5, 6 and 7 illustrate various portions of the core 40 after it hasbeen subjected to the magnetic drawing action within the compressingassembly to form an increased thickness of the coating materialintermixed with magnetic particles at selected surfaces of the core;e.g., slot corners and edges.

The core 40, as illustrated in this exemplification, has a yoke section,70 and tooth sections 72 defining winding-receiving slots 74. Thematerial 76 covers the entire outer surface of the end laminations 78and 80 and the slots 74. However, the

physical masking action of the air supplied through the core supportandv masking assembly 56, as defined in more detail in I theaforementioned F ritzsche copending application, prevents a coating frombeing formed on the curved end portions 82 and 84 of each tooth section72. The support and masking as- I sembly 56 also masks from the coatingmaterial the bore of the core as defined by the ends of the toothsection 72. F lGS.57 also illustrates the increased thickness of coatingmaterial at the edges and corners of the tooth sections and slots ofcore 40. This increased thickness is produced by the action of themagnetic field produced by the electromagnet assembly 42 of thecompressing assembly 10 illustrated in FIG. 1.

It should be apparent to those skilled in the art that while a preferredembodiment of the invention has been described and illustrated inaccordance with the Patent Statutes,

changes may .be made in disclosed embodiments without actually departingfrom the true spirit and scope of this invention as defined inthefollowing claims which are intended to cover all such equivalentvariations as fall within the invention.

I claim: 1. An apparatus for compressing laminated article comprismg:

a. an electromagnet assembly, a

b. support means fixedto said electromagnet assembly for supporting alaminated articlewithin said assembly,

c. stop means adjustably mounted on said support means for engaging oneside of the article on said support means,

d. clamping means mounted in said electromagnet assembly for engagingtheopposite side of the laminated article and urging the article towardsaid stop means,

e. means for electrically energizing said electromagnet assembly forproducing a magnetic field, whereby the laminations of. said article aremechanically compressed between said stop means and said clamping meansand opening and aligned with the axis of the toroid, and wherein thelaminated article is slidable on said supportmeans,

whereby the article on said support means is drawn generally to acentral position within said electromagnet by the magnetic fieldproduced when said electromagnet assembly is energized.

3. The apparatus defined in claim 2, wherein said clamping means furthercomprises a plurality of clamps, and means normally biasing said clampsinto a position within the opening such that they would engage saidopposite side of an article when disposed at said central positionwithin said electromagnet. I

4. The apparatus defined in claim 3 wherein said clamping means furthercomprises a rod fixed to each of said clamps and mounted for rotationaland longitudinal movement in said electromagnet assembly, means forapplying to each of the rods a force opposite to that of said biasingmeans to move said clamps longitudinally out of said opening, and meansfor rotating said rods to move' said clamps generally radially out ofsaid opening.

5. The apparatus defined in claim 4 wherein the means for rotatingcomprises a pin on each rod, said pin riding in a camming slot in saidelectromagnet assembly, the slot being shaped to rotate said rod whensaid rod moves longitudinally.

6. The apparatus defined in claim 4 wherein the biasing means comprisesa spring associated with each of said rods.

1. An apparatus for compressing laminated article comprising: a. anelectromagnet assembly, b. support means fixed to said electromagnetassembly for supporting a laminated article within said assembly, c.stop means adjustably mounted on said support means for engaging oneside of the article on said support means, d. clamping means mounted insaid electromagnet assembly for engaging the opposite side of thelaminated article and urging the article toward said stop means, e.means for electrically energizing said electromagnet assembly forproducing a magnetic field, whereby the laminations of said article aremechanically compressed between said stop means and said clamping meansand magnetically compressed by the magnetic field.
 2. The apparatusdefined in claim 1 wherein said electromagnet assembly comprises asubstantially toroid-shaped electromagnet having a substantiallycircular central opening therein, and wherein said support means isdisposed in said opening and aligned with the axis of the toroid, andwherein the laminated article is slidable on said support means, wherebythe article on said support means is drawn generally to a centralposition within said electromagnet by the magnetic field produced whensaid electromagnet assembly is energized.
 3. The apparatus defined inclaim 2, wherein said clamping means further comprises a plurality ofclamps, and means normally biasing said clamps into a position withinthe opening such that they would engage said opposite side of an articlewhen disposed at said central position within said electromagnet.
 4. Theapparatus defined in claim 3 wherein said clamping means furthercomprises a rod fixed to each of said clamps and mounted for rotationaland longitudinal movement in said electromagnet assembly, means forapplying to each of the rods a force opposite to that of said biasingmeans to move said clamps longitudinally out of said opening, and meansfor rotating said rods to move said clamps generally radially out ofsaid opening.
 5. The apparatus defined in claim 4 wherein the means forrotating comprises a pin on each rod, said pin riding in a camming slotin said electromagnet assembly, the slot being shaped to rotate said rodwhen said rod moves longitudinally.
 6. The apparatus defined in claim 4wherein the biasing means comprises a spring associated with each ofsaid rods.